svl/source/notify/lstner.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <svl/lstner.hxx>
  21
  22 #include <svl/hint.hxx>
  23 #include <svl/SfxBroadcaster.hxx>
  24 #include <sal/backtrace.hxx>
  25 #include <sal/log.hxx>
  26
  27 #include <algorithm>
  28 #include <cassert>
  29 #include <vector>
  30 #include <memory>
  31 #include <map>
  32
  33 struct SfxListener::Impl
  34 {
  35     std::vector<SfxBroadcaster*> maBCs;
  36 #ifdef DBG_UTIL
  37     std::map<SfxBroadcaster*, std::unique_ptr<sal::BacktraceState>>
  38         maCallStacks;
  39 #endif
  40 };
  41
  42 // simple ctor of class SfxListener
  43
  44 SfxListener::SfxListener() : mpImpl(new Impl)
  45 {
  46 }
  47
  48 // copy ctor of class SfxListener
  49
  50 SfxListener::SfxListener( const SfxListener &rListener ) : mpImpl(new Impl)
  51 {
  52     for ( size_t n = 0; n < rListener.mpImpl->maBCs.size(); ++n )
  53         StartListening( *rListener.mpImpl->maBCs[n] );
  54 }
  55
  56 // unregisters the SfxListener from its SfxBroadcasters
  57
  58 SfxListener::~SfxListener() COVERITY_NOEXCEPT_FALSE
  59 {
  60     // unregister at all remaining broadcasters
  61     for ( size_t nPos = 0; nPos < mpImpl->maBCs.size(); ++nPos )
  62     {
  63         SfxBroadcaster *pBC = mpImpl->maBCs[nPos];
  64         pBC->RemoveListener(*this);
  65     }
  66 }
  67
  68
  69 // unregisters a specific SfxBroadcaster
  70
  71 void SfxListener::RemoveBroadcaster_Impl( SfxBroadcaster& rBroadcaster )
  72 {
  73     auto it = std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster );
  74     if (it != mpImpl->maBCs.end()) {
  75         mpImpl->maBCs.erase( it );
  76 #ifdef DBG_UTIL
  77         mpImpl->maCallStacks.erase( &rBroadcaster );
  78 #endif
  79     }
  80 }
  81
  82
  83
  84 /**
  85  Registers a specific SfxBroadcaster.
  86
  87  Some code uses duplicates as a kind of ref-counting thing i.e. they add and remove listeners
  88  on different code paths, and they only really stop listening when the last EndListening() is called.
  89 */
  90 void SfxListener::StartListening(SfxBroadcaster& rBroadcaster, DuplicateHandling eDuplicateHanding)
  91 {
  92     bool bListeningAlready = IsListening( rBroadcaster );
  93
  94 #ifdef DBG_UTIL
  95     if (bListeningAlready && eDuplicateHanding == DuplicateHandling::Unexpected)
  96     {
  97         auto f = mpImpl->maCallStacks.find( &rBroadcaster );
  98         SAL_WARN("svl", "previous StartListening call came from: " << sal::backtrace_to_string(f->second.get()));
  99     }
 100 #endif
 101     assert(!(bListeningAlready && eDuplicateHanding == DuplicateHandling::Unexpected) && "duplicate listener, try building with DBG_UTIL to find the other insert site.");
 102
 103     if (!bListeningAlready || eDuplicateHanding != DuplicateHandling::Prevent)
 104     {
 105         rBroadcaster.AddListener(*this);
 106         mpImpl->maBCs.push_back( &rBroadcaster );
 107 #ifdef DBG_UTIL
 108         mpImpl->maCallStacks.emplace( &rBroadcaster, sal::backtrace_get(10) );
 109 #endif
 110         assert(IsListening(rBroadcaster) && "StartListening failed");
 111     }
 112 }
 113
 114 // unregisters a specific SfxBroadcaster
 115
 116 void SfxListener::EndListening( SfxBroadcaster& rBroadcaster, bool bRemoveAllDuplicates )
 117 {
 118     auto beginIt = mpImpl->maBCs.begin();
 119     do
 120     {
 121         auto it = std::find( beginIt, mpImpl->maBCs.end(), &rBroadcaster );
 122         if ( it == mpImpl->maBCs.end() )
 123         {
 124             break;
 125         }
 126         rBroadcaster.RemoveListener(*this);
 127         beginIt = mpImpl->maBCs.erase( it );
 128 #ifdef DBG_UTIL
 129         mpImpl->maCallStacks.erase( &rBroadcaster );
 130 #endif
 131     }
 132     while ( bRemoveAllDuplicates );
 133 }
 134
 135
 136 // unregisters all Broadcasters
 137
 138 void SfxListener::EndListeningAll()
 139 {
 140     std::vector<SfxBroadcaster*> aBroadcasters;
 141     std::swap(mpImpl->maBCs, aBroadcasters);
 142     for (SfxBroadcaster *pBC : aBroadcasters)
 143         pBC->RemoveListener(*this);
 144 #ifdef DBG_UTIL
 145     mpImpl->maCallStacks.clear();
 146 #endif
 147 }
 148
 149
 150 bool SfxListener::IsListening( SfxBroadcaster& rBroadcaster ) const
 151 {
 152     return mpImpl->maBCs.end() != std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster );
 153 }
 154
 155 sal_uInt16 SfxListener::GetBroadcasterCount() const
 156 {
 157     return mpImpl->maBCs.size();
 158 }
 159
 160 SfxBroadcaster* SfxListener::GetBroadcasterJOE( sal_uInt16 nNo ) const
 161 {
 162     return mpImpl->maBCs[nNo];
 163 }
 164
 165
 166 // base implementation of notification handler
 167
 168 void SfxListener::Notify( SfxBroadcaster& rBroadcaster, const SfxHint& )
 169 {
 170     (void) rBroadcaster;
 171     assert(IsListening(rBroadcaster));
 172 }
 173
 174 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */